Driving and braking device



R. M: DILWORTH DRIVING AND BRAKING DEVICE May 4, 1948.

Filed Feb. 7, 1944 2 Sheets-Sheet 1 3 uentor %,&2 7%? attorney:

May 4, 1948; R. DILWORTH DRIVING AND BRAKING DEVICE Filed Feb. 7 1944 2 Sheets-Sheet 2 2 f J 0 WWW w 7/ 4 i i a H. 3 w, I 1.. v J z a M I a m 1 a a w v a w a p z J m w .w a a Q. y d a Patented May 4, 1948 DRIVING AND BRAKING DEVICE Richard M. Dilworth, Hinsdale, Ill., asaignor to General Motors Corporation, Detroit, Mich,, a

corporation of Delaware Application February 7, 1944, Serial No. 521,391

1 The present invention generally relates to frictional driving and braking means and more par- 7 Claims. (Cl. 230-271) ticularly relates to combined driving and braking means of the fluid actuated type. I

The principal object of the present invention is to provide a, simple and compact driving and braking assembly including a single fluid-distensible actuating member for causing smooth engagement of either the driving or the braking means.

The assembly by which the above object is accomplished will become apparent by reference to the following detailed description and accompanying drawings illustrating one form of the invention which is particularly adapted to ver-' tical shaft drives for ventilating fans.

Figure l of the drawings is an elevation view of the complete assembly of the driving and braking means for a ventilating fan with certain parts broken away, and

Figure 2 of the drawings is an enlarged axial section of the assembly with certain of the parts broken away to show details of certain of the parts to better advantage. i

As best shown in Figure 1, the fan driving and braking assembly is enclosed in a cylindrical housing I provided with an upper external mounting flange t for supporting the housing in a vertical position. The housing is open at the bottom and is provided with a housing cap 5 having a screened opening 7 for the passage of air longitudinally through the housing.

As best shown in Figure 2, driven, supporting and driving members, respectively indicated generally at El, ii and i3, are arranged coaxially with the housing.

' the driven member 9. A flexible annular pneu- The driven member 9 comprises a drum-shaped hub provided with axially spaced internal flanges l5 and I l and fan blades i9 extending radially outwardly therefrom and shown located adjacent the screened opening i in the housing cap 5. The hub flange H is removably secured to the member 9 and is provided with a, concentric rib 20 on the outer radial face thereof having an external conical braking and supporting surface 23 4 which normally rests on an internal conical brak- "bore in'the driving flange hub portion 49.

2 with a radially extending hub portion 21 and a peripheral portion, indicated generally at 29,

which extends into the space between the axially spacedintemal flanges l5 and ll of the driven member 8. The peripheral portion 29 of the driving member is of annular trough shaped form having a bottom portion ll extending between and parallel to the internal flanges l5 and ll of the driven member 9, and side wall portions l3 and 35 diverging from the bottom portion 3| and extending toward the internal flange 15 of matic rubber tire 31 of substantially rectangular cross section is positioned in the annular groove of the driving member and is secured thereto by vulcanizing one radial face of the tire to the inner radial face of thev bottom portion 3| of the annular trough portion of the, driving member. The opposite radial face of the tire is provided with a ribbed surface 35 for frictional driving engagement with the flange' H of the driven member 9, and a ring of friction material 4| is secured to the outer radial face of the portion H of the driving member i3 for frictional driving engagement with the other flange Ill of the driven member 8.

The hub portion 21! oi the driving member is secured by bolts 43 to a driving flange 45 provided with axially extending hub portions 41 and 49. The flange and hub portions are bored axial-'- ly and the hub portion 41 extends through a hole in the hub portion 21 of the driving member 83 and is splined on the end of a driving shaft 5!, shown extending coaxial with respect to the driven, driving and supporting members. A plug 53 having an axial bore and a radial passage 51 registering therewith, is threaded in the axial A stud 59, having a gasket 6i under the head, extends through the axial bore 55 of the plug 53 and is threaded into an axial bore in the end of the driving shaft 5! to prevent relative axial movement between the driving flange 45 and driving shaft 5 I The driving flange 45 and driving shaft 5! ar supported for coaxial rotation with respect to the driven and supporting ,member by means of thrust A spacing sleeve is also placed between the outer race of the bearing 65 and an internal shoulder 11 adjacent one end of the bearing housing 51 and another spacing sleeve 18 is placed between the outer race of the bearing 85 and an end closure plate 8| secured to the other end of the housing by cap screws 88. The closure plate 8| has an opening in which an oil retaining sleeve 85 is secured. This sleeve surrounds the driving shaft and extends to point adjacent in the inner race of the bearing 85. The other end of the bearing housing 61 is closed by a lionsing cap 81 secured thereto bymachine screws 88. The housing cap 81 also contacts the outer race of the bearing 83 and the hub "of the driving flange 45 projects through an opening in the cap 81.

Lubricating oil is supplied through a pipe 8! shown extending through an opening in the clo-, sure plate 8| and is threaded in a longitudinal passage 83 in the bearing housing. The oil passage 83 communicates with aligned radial passages indicated at 85 in the bearing housing 81 and cap 81 so that oil enters the bearing housing 81 through the bearing 63. Oil passes from the bearing housing through a drain pipe 81 threaded dered portion of the plug 53 and the outer bearspacing sleeve I81 which is secured in the. cap

by an air tube v I I8 connected toan opening in the cap and extending through an opening in the sleeve I81.

Air pressure is conducted to and vented from the pneumatic tire 31 by means of the tube. H3. The inner end of the tube H3 terminates in a space H5 in the cap 99 between the bearing lill' and thehub portion 38 of the driving flange 45. The space H5 by reason of the axial and radial openings 55 and 51 in the plug 53 is placed in communication with the space H1 in the driving flange 49 between the plug 53 and the end of the driving shaft 5!. A passage H9 in the driving flange communicates with the space ill and a tube l2l is connected between the interior of the tire 31 and the passage '8.

Operation of the above described assembly is briefly as follows: With the parts of the assembly in the positions shown, the driving member i3 is freely rotatable with respect to the driven member 8 which is supported in spaced concentric relation with respect to the driving member by engagement of the conical supporting and braking surface of the lower flange 11 of the driven member with the conical supporting and braking surface of the stationary supporting member ll.

Upon initial inflation of the tire, the upper ribbed ward movement thereof. The lower flange I1 of the driven member is accordingly moved gradually upwardly causing the conical supporting and braking surface of the flange l1 to be gradually moved out of braking supporting contact with the conical surface on the supporting member. The driven member 9 and fan blades I!) are accordingly accelerated gradually by gradual engagement with the driving member and gradual disengagement from the supporting member. Further inflation of the tire causes further upward movement of the driven member which causes the 'upper surface of the flange l1 of the driven member to engage the friction material 4| secured to the lower face of the driving member thereby clamping the driven member in frictional and supporting driving relation with the driving member thereby causing rotation of the driven member and the-fan blades 19 thereon at the speed of the'driving member. The air moved by these fan blades circulates freely in the housing I to cool the frictional engaging surfaces of the driving, driven and supporting members. Deflation of the tire 31 conversely causes gradual movement of the driven member downwardly which successively causes gradual disengagement between the above mentioned lower and upper driving and supporting surfaces provided on the driving and driven members and gradual engagement of the conical supporting and braking surfaces provided on the driven and stationary supporting members, thereby causing deceleration of the driven 'member to rest.

I claim:

l. A driving assembly comprising a driving member, a driven member, stationary means for normally supporting said members in coaxial relation and a resilient fluid pressure expansible tube in concentric relation between said driving and driven members for controlling gradual axial movement of said driven member out of supporting relation on said stationary means and into resilient supporting and driving engagement with said driving member.

2. A driving and braking assembly comprising a driving member, a driven member, stationary means for supporting said members, said means including bearings for rotatably supportin said driving member and a braking surface adapted,

en members for controlling gradual axial move-.

ment of said driven member out of supporting relation on the braking surface of said stationary means andinto resilient supporting and driving engagement with said driving member.

3. .A driving and braking assembly comprising a stationary support member having a circular supporting and braking surface, a driven drum having internal flanges and an external surface normally engaging the supporting and braking surface of said support member, a circular driving member having a pneumatic tire secured to one side thereof, said driving member and tire being rotatably supported in concentric relation between the flanges of said driven drum so that upon inflation of said tire the driven drumvis moved out of supporting and braking engagement with said support member and clamped in concentric relation to said driving member for rotation thereby.

4,-A driving and braking assembly comprising a stationary support member having a circular depression therein, a driven drum supported .in said depression, said drum having internal flanges, a driving member having an annular depression therein, a pneumatic tire in said annular depression, said driving member being supported for rotation by said support member in concentric relation within said drum between the flanges thereof, and means for inflating and deflating said tire to cause said drum to be moved into clamp-u surface normally resting in said conical depression in said stationary member so that said drum 7 flanges extend on either side of the annular depression in said driving member, and rotary pressure sealing means supported on and cooperating with said driving member and tire for causing inflating or deflating said tire to cause said driven drum to be moved into clamping and supporting engagement with said'driving member or supported on said stationary member.

6. A fan driving and braking assembly com prising a stationary member having a conical braking and positioning surface, a fan having a drum-shaped hub with internal flanges and a concentric conical braking and supporting surface supported in and positioned by the conical braking and positioning surface of the stationary member, a driving member having an annular depression supported for rotation in said stationary I member about the axis of the conical braking and positioning surface thereof, the annular depression in the driving member being positioned between the flanges of said fan drum, a fluid distensible tire supported in the annular depression in the driving member, and rotary sealing means cooperating with said-driving member and tire for causing fluid pressure to be applied to or prising a vertical housing, a support member secured transversely in said housing, said member being provided with air passages therethrough and a conical supporting and braking surface, a driving shaft supported for rotation in said memher about the axis of the conical surface, a driving member secured to said shaft, said driving member having an annular depression therein, a pneumatic clutch tire secured to the bottom of said annular depression, a pressure sealing member cooperating with said driving member and connected to said tire to permit inflation or deflation thereof in order to cause expansion or contraction thereof, a fan having a hub portion provided with axially spaced internal flanges and a lower conical surface normally guided and supported on the conical supporting and braking surface of said support member in order to position internal flanges of said fan hub adjacent the upper surface of said tire and lower surface of the annular depression of said driving member so that upon inflation of said tire the fan will be moved upwardly out of frictional and supporting contact with said support member and will be clamped in concentric relation to said driving member by the force exerted by said tire on the flanges of a the fan hub and when deflated said fanwi-ll be moved downwardly out of contact with said driving member and into normal contact with said support member. RICHARD M. DILWOR'I'H.

nsmasnoss man UNITED STATES PATENTS Number Name Date Brewer Jan. 4, 1938 Klein May 6, 1930 4 

